Field
Embodiments disclosed herein generally relate to a slit valve door and a method for sealing a chamber with a slit valve door.
Description of the Related Art
In semiconductor, flat panel display, photovoltaic/solar panel, and other substrate processing systems, it is common to arrange vacuum chambers (i.e., load lock chambers, transfer chambers, process chambers) in a cluster, in-line, or a combination of cluster/in-line arrangements in order to process substrates. These systems may process substrates in single or batch substrate fashion. During processing, substrates may be transferred to and from chambers in which vacuum must be maintained or established. To allow access to the inside of the chamber, and to enable vacuum operation, a substrate transfer port formed through the chamber wall in the shape of a slit is frequently provided to accommodate the substrate being processed. The substrate transfer port is opened and closed (e.g., sealed) by a slit valve assembly.
The slit valve assembly includes a slit valve door that may be movably actuated to open or close the substrate transfer port. When the slit valve door is clear of the substrate transfer port, one or more substrates may be transferred between two vacuum chambers through the substrate transfer port. When the slit valve port is closed and sealed by the slit valve door, substrates may not be transferred in or out of vacuum chambers through the substrate transfer port and the vacuum chambers remain sealed. For example, two vacuum chambers connected by a slit valve assembly may include a process or transfer chamber which requires periodic isolation from a load lock chamber in order to maintain vacuum in the process or transfer chamber when the load lock chamber is vented.
Generally, the operational speed of the slit valve door is important to the throughput of substrate processing system. However, faster door operations result in large shocks or vibrations as the slit valve door opens and closes. The shocks may loosen and disperse particles within the vacuum chambers, which may create defects on the substrate. This may be particularly important in the processing of organic light emitting diode (OLED) substrates as well as thin film encapsulation (TFE) processes where contamination should be kept at a minimum. Additionally, large shocks over time may loosen fasteners and increase wear on the components of the slit valve door and the slit valve assembly.
Therefore, there is a need for a slit valve assembly capable of sealing chambers with reduced shock.